<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Captcha
 * @subpackage Adapter
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */

/** Zend_Captcha_Base */
require_once 'Zend/Captcha/Base.php';

/**
 * Word-based captcha adapter
 *
 * Generates random word which user should recognise
 *
 * @category   Zend
 * @package    Zend_Captcha
 * @subpackage Adapter
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Word.php 16971 2009-07-22 18:05:45Z mikaelkael $
 */
abstract class Zend_Captcha_Word extends Zend_Captcha_Base
{
	/**#@+
	 * @var array Character sets
	 */
	static $V  = array("a", "e", "i", "o", "u", "y");
	static $VN = array("a", "e", "i", "o", "u", "y","2","3","4","5","6","7","8","9");
	static $C  = array("b","c","d","f","g","h","j","k","m","n","p","q","r","s","t","u","v","w","x","z");
	static $CN = array("b","c","d","f","g","h","j","k","m","n","p","q","r","s","t","u","v","w","x","z","2","3","4","5","6","7","8","9");
	/**#@-*/

	/**
	 * Random session ID
	 *
	 * @var string
	 */
	protected $_id;

	/**
	 * Generated word
	 *
	 * @var string
	 */
	protected $_word;

	/**
	 * Session
	 *
	 * @var Zend_Session_Namespace
	 */
	protected $_session;

	/**
	 * Class name for sessions
	 *
	 * @var string
	 */
	protected $_sessionClass = 'Zend_Session_Namespace';

	/**
	 * Should the numbers be used or only letters
	 *
	 * @var boolean
	 */
	protected $_useNumbers = true;

	/**
	 * Should both cases be used or only lowercase
	 *
	 * @var boolean
	 */
	// protected $_useCase = false;

	/**
	 * Session lifetime for the captcha data
	 *
	 * @var integer
	 */
	protected $_timeout = 300;

	/**#@+
	 * Error codes
	 * @const string
	 */
	const MISSING_VALUE = 'missingValue';
	const MISSING_ID    = 'missingID';
	const BAD_CAPTCHA   = 'badCaptcha';
	/**#@-*/

	/**
	 * Error messages
	 * @var array
	 */
	protected $_messageTemplates = array(
	self::MISSING_VALUE => 'Empty captcha value',
	self::MISSING_ID    => 'Captcha ID field is missing',
	self::BAD_CAPTCHA   => 'Captcha value is wrong',
	);

	/**
	 * Length of the word to generate
	 *
	 * @var integer
	 */
	protected $_wordlen = 8;

	/**
	 * Retrieve session class to utilize
	 *
	 * @return string
	 */
	public function getSessionClass()
	{
		return $this->_sessionClass;
	}

	/**
	 * Set session class for persistence
	 *
	 * @param  string $_sessionClass
	 * @return Zend_Captcha_Word
	 */
	public function setSessionClass($_sessionClass)
	{
		$this->_sessionClass = $_sessionClass;
		return $this;
	}

	/**
	 * Retrieve word length to use when genrating captcha
	 *
	 * @return integer
	 */
	public function getWordlen()
	{
		return $this->_wordlen;
	}

	/**
	 * Set word length of captcha
	 *
	 * @param integer $wordlen
	 * @return Zend_Captcha_Word
	 */
	public function setWordlen($wordlen)
	{
		$this->_wordlen = $wordlen;
		return $this;
	}

	/**
	 * Retrieve captcha ID
	 *
	 * @return string
	 */
	public function getId ()
	{
		if (null === $this->_id) {
			$this->_setId($this->_generateRandomId());
		}
		return $this->_id;
	}

	/**
	 * Set captcha identifier
	 *
	 * @param string $id
	 * return Zend_Captcha_Word
	 */
	protected function _setId ($id)
	{
		$this->_id = $id;
		return $this;
	}

	/**
	 * Set timeout for session token
	 *
	 * @param  int $ttl
	 * @return Zend_Captcha_Word
	 */
	public function setTimeout($ttl)
	{
		$this->_timeout = (int) $ttl;
		return $this;
	}

	/**
	 * Get session token timeout
	 *
	 * @return int
	 */
	public function getTimeout()
	{
		return $this->_timeout;
	}

	/**
	 * Get session object
	 *
	 * @return Zend_Session_Namespace
	 */
	public function getSession()
	{
		if (!isset($this->_session) || (null === $this->_session)) {
			$id = $this->getId();
			if (!class_exists($this->_sessionClass)) {
				require_once 'Zend/Loader.php';
				Zend_Loader::loadClass($this->_sessionClass);
			}
			$this->_session = new $this->_sessionClass('Zend_Form_Captcha_' . $id);
			$this->_session->setExpirationHops(1, null, true);
			$this->_session->setExpirationSeconds($this->getTimeout());
		}
		return $this->_session;
	}

	/**
	 * Set session namespace object
	 *
	 * @param  Zend_Session_Namespace $session
	 * @return Zend_Captcha_Word
	 */
	public function setSession(Zend_Session_Namespace $session)
	{
		$this->_session = $session;
		return $this;
	}

	/**
	 * Get captcha word
	 *
	 * @return string
	 */
	public function getWord()
	{
		if (empty($this->_word)) {
			$session     = $this->getSession();
			$this->_word = $session->word;
		}
		return $this->_word;
	}

	/**
	 * Set captcha word
	 *
	 * @param  string $word
	 * @return Zend_Captcha_Word
	 */
	protected function _setWord($word)
	{
		$session       = $this->getSession();
		$session->word = $word;
		$this->_word   = $word;
		return $this;
	}

	/**
	 * Generate new random word
	 *
	 * @return string
	 */
	protected function _generateWord()
	{
		$word       = '';
		$wordLen    = $this->getWordLen();
		$vowels     = $this->_useNumbers ? self::$VN : self::$V;
		$consonants = $this->_useNumbers ? self::$CN : self::$C;

		for ($i=0; $i < $wordLen; $i = $i + 2) {
			// generate word with mix of vowels and consonants
			$consonant = $consonants[array_rand($consonants)];
			$vowel     = $vowels[array_rand($vowels)];
			$word     .= $consonant . $vowel;
		}

		if (strlen($word) > $wordLen) {
			$word = substr($word, 0, $wordLen);
		}

		return $word;
	}

	/**
	 * Generate new session ID and new word
	 *
	 * @return string session ID
	 */
	public function generate()
	{
		$this->_session = null;
		$id             = $this->_generateRandomId();
		$this->_setId($id);
		$word           = $this->_generateWord();
		$this->_setWord($word);
		return $id;
	}

	protected function _generateRandomId()
	{
		return md5(mt_rand(0, 1000) . microtime(true));
	}

	/**
	 * Validate the word
	 *
	 * @see    Zend_Validate_Interface::isValid()
	 * @param  mixed $value
	 * @return boolean
	 */
	public function isValid($value, $context = null)
	{
		if (!is_array($value) && !is_array($context)) {
			$this->_error(self::MISSING_VALUE);
			return false;
		}
		if (!is_array($value) && is_array($context)) {
			$value = $context;
		}

		$name = $this->getName();

		if (isset($value[$name])) {
			$value = $value[$name];
		}

		if (!isset($value['input'])) {
			$this->_error(self::MISSING_VALUE);
			return false;
		}
		$input = strtolower($value['input']);
		$this->_setValue($input);

		if (!isset($value['id'])) {
			$this->_error(self::MISSING_ID);
			return false;
		}

		$this->_id = $value['id'];
		if ($input !== $this->getWord()) {
			$this->_error(self::BAD_CAPTCHA);
			return false;
		}

		return true;
	}

	/**
	 * Get captcha decorator
	 *
	 * @return string
	 */
	public function getDecorator()
	{
		return "Captcha_Word";
	}
}
